Which of the following is the first life-threatening injury to address?

In addressing life-threatening injuries, stopped breathing is crucial because it directly affects oxygen supply to the brain and other vital organs. Without adequate oxygen, cells begin to die, which can lead to irreversible damage within minutes. Maintaining airflow is essential for survival; if an individual is not breathing, immediate action is required to restore normal respiratory function.

While no heartbeat, loss of consciousness, and severe bleeding are critical issues, they follow a chain of priority that typically hinges on restoring breathing first. In a situation where breathing has stopped but the heart is still beating, performing rescue breaths can be life-saving. The combination of oxygenation through breaths and potential heart revival through CPR can consequently stabilize the patient, making it imperative to address cessation of breathing immediately.